Yosemite National Park. 



215 



ern limit of the jointed quarriable rock, and here the Yosemite 

 Valley ends. The rock continues down the course of the Mer- 

 ced as far as The Gateway, and this explains the narrowness of 

 the gorge. 



An Impressive View from Glacier Point 



The lower end of the valley is of interest because a consider- 

 able part of the mass of the Yosemite Glacier had to move up- 



Photo by F. E. Matthes, U. S. Geol. Survey 



FIG. 68. Glacial floor and side of Merced Canyon. The rocks have 

 been smoothed and polished by glacier ice. The row of stones in the fore- 

 ground marks the trail across the smooth rock floor. 



ward over the hard (El Capitan) granite to get out of the val- 

 ley. The central portion of the glacier passed through the 

 Merced Gorge, but the ice outside of this rode up and over the 

 rock slope. Debris carried by the ice, and markings left on 

 the rock surface by the moving ice, show that the ice pushed up 



